New TimeSeries.notch method
This PR adds a new module for filtering utilies under the timeseries
namespace for generating filters, and a new TimeSeries.notch
instance method to notch out a specific frequency (in Hertz).
This PR adds a new module for filtering utilies under the timeseries
namespace for generating filters, and a new TimeSeries.notch
instance method to notch out a specific frequency (in Hertz).